cubic-spline-interpolation https://github.com/Simsso/Online-Tools/blob/686eb7dd9e43accac273c466e2d66fa64dd1928f/src/page/logic/cubic-spline-interpolation.js#L63 https://github.com/Simsso/Online-Tools/blob/686eb7dd9e43accac273c466e2d66fa64dd1928f/src/page/adapter/cubic-spline-interpolation.js#L249